CN103078517A - Generation device and method for magnetizing inrush current of three-phase transformer - Google Patents
Generation device and method for magnetizing inrush current of three-phase transformer Download PDFInfo
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- CN103078517A CN103078517A CN2012105779910A CN201210577991A CN103078517A CN 103078517 A CN103078517 A CN 103078517A CN 2012105779910 A CN2012105779910 A CN 2012105779910A CN 201210577991 A CN201210577991 A CN 201210577991A CN 103078517 A CN103078517 A CN 103078517A
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Abstract
The invention relates to a generation device and a generation method for magnetizing inrush current of a three-phase transformer, belonging to the technical field of power system application experimental research. The technical scheme is that three groups of two thyristors and one alternating current contactor, which are reversely connected in parallel, are connected in parallel to form a composite switch which is connected in series between front ends of three-phase transformers and a breaker; a trigger signal is provided through an opening and closing control trigger plate, so that the thyristors are triggered at a specified phase angle, and closing at a required voltage phase angle is realized; and different voltage closing phase angles are generated by the opening and closing control trigger plate to generate different magnetizing inrush current values. According to the device and the method, the situation of the magnetizing inrush current of a power system is simulated under a low-voltage safety condition, and various magnetizing inrush current working conditions are analyzed. Magnetizing inrush current waveform for forming readable data can be compared with a calculation result, so that comparative verification of calculation and testing is facilitated; and through application of the composite switch, the correctness and the reliability of research work are further guaranteed.
Description
Technical field
The present invention relates to a kind of generation device and method of three-phase transformer magnetizing inrush current, belong to electric power system Applied experimental study technical field.
Background technology
During the no-load transformer operation, one side winding (high pressure or low pressure) is charged, other winding open circuit.Electric current in the winding is exciting current, and the magnetic flux in the iron core is work magnetic flux Φ m.When the combined floodgate transient voltage was null value, the stable state magnetic flux maximum that it is set up in iron core was (Φ m).Owing to the magnetic flux in the iron core can not suddenly change, and magnetic flux is zero in the front iron core that closes a floodgate, and it is zero that the rear moment of then closing a floodgate also should keep magnetic flux.Therefore, be engraved in the transient state magnetic flux Φ tr that just occurs an aperiodic component in the iron core this moment, and its amplitude is Φ m.At this moment, the total magnetic flux Φ in the iron core should regard two magnetic fluxs as and is formed by stacking.To begin be zero to magnetic flux in the iron core, and during to 1/2 T, two magnetic flux additions reach maximum, and the maximum of Φ waveform is the twice near Φ m.If in the iron core remanent magnetism Φ r is arranged when closing a floodgate, and the polarity of Φ r is identical with Φ tr.Magnetic flux Φ also can be larger, surpasses saturation flux Φ s unshakable in one's determination.This state makes transformer produce the very large magnetizing inrush current of instantaneous peak value.For large-scale power transformer, the exciting current of stable state only has the some thousandths of of rated operational current.Its amplitude of this magnetizing inrush current may reach several thousand times of exciting current, reaches several times or tens times of rated current.This is just so that transformer during no-load closing, or during recovery after power cut voltage, and circuit breaker often moves tripping operation, causes power transformer normally not put into operation timely; The protective device tripping operation, simultaneously large shoving produces large electric power to winding, may cause winding stress deformation damage etc.Disconnect large magnetizing inrush current and may cause overvoltage, its value surpasses the operating impulse voltage of general electrical network, and the insulation of transformer is worked the mischief.Magnetizing inrush current causes supersaturation unshakable in one's determination, because the magnetostrictive effect of electrical steel sheet, transformer vibration and noise can increase, the harm transformer.Simultaneously, the magnetizing inrush current that transformer air-drop produces brings out that the transformer that is moving in contiguous other power stations produces " and echo surge current " and mistrip causes large-area power-cuts; DC component in the magnetizing inrush current causes the current transformer magnetic circuit excessively to be magnetized and significantly reduces the performance factor of certainty of measurement and protective relaying device; A large amount of harmonic waves in the magnetizing inrush current cause serious pollution to the electrical network quality of power supply.In order to finish the mechanism of production of magnetizing inrush current and the research work of braking measure in laboratory, a kind of generation device and method of three-phase transformer magnetizing inrush current is badly in need of in this area, is convenient in the laboratory three-phase transformer magnetizing inrush current be studied.
Summary of the invention
The object of the invention provides a kind of generation device and method of three-phase transformer magnetizing inrush current, is used for the production of research magnetizing inrush current.Introduce large magnetizing inrush current when researching and solving the three-phase transformer idle-loaded switching-on, cause the unsettled problem of electric power system.By the study tour of this parameter, formulate the numerical value of adjusting of the protective device of transformer, solve the problems referred to above that exist in the background technology.
Technical scheme of the present invention is:
A kind of generation device of three-phase transformer magnetizing inrush current, comprise circuit breaker, thyristor, A.C. contactor, on/off switch control trigger board and three phase transformers, two thyristors and an A.C. contactor of three groups of reverse parallel connections compose in parallel a combination switch, are connected between the front end and circuit breaker of three transformers; Provide triggering signal by on/off switch control trigger board, thyristor is triggered at the phase angle of regulation, close a floodgate when being implemented in the required voltage phase angle; On/off switch control trigger board produces different voltage switching-on phase angles, produces different magnetizing inrush current values; Simultaneously, current continuity in first cycle of thyristor, cutoff thyristor behind the one-period closes a floodgate successfully in the one-period of A.C. contactor after thyristor closes a floodgate, and guarantees current continuity, realizes separating brake control by A.C. contactor.
The present invention also is provided with host computer, and control on/off switch control trigger board produces different voltage switching-on phase angles, produces different magnetizing inrush current values.
The present invention also is provided with TT﹠C system, comprises oscilloscope, ammeter pincers and voltmeter pincers, cooperates ammeter pincers and voltmeter pincers to carry out voltage acquisition and current acquisition with oscilloscope, finishes magnetizing inrush current is measured.
A kind of method of using said apparatus to produce the three-phase transformer magnetizing inrush current provides triggering signal by on/off switch control trigger board, and thyristor is triggered at the phase angle of regulation, closes a floodgate when being implemented in the required voltage phase angle; Closing a floodgate in the different voltage switching-on phase angle of on/off switch control trigger board control, can produce different magnetizing inrush current values; Simultaneously, current continuity in first cycle of thyristor, cutoff thyristor behind the one-period closes a floodgate successfully in the one-period of A.C. contactor after thyristor closes a floodgate, and guarantees current continuity, realizes separating brake control by A.C. contactor.
Also be provided with host computer, the work of control on/off switch control trigger board.
By comprising the TT﹠C system of oscilloscope, ammeter pincers and voltmeter pincers, cooperate ammeter pincers and voltmeter pincers to carry out voltage acquisition and current acquisition with oscilloscope, finish magnetizing inrush current is measured.
The present invention is adapted at finishing in the laboratory relevant Task, breaks away from the place that large-scale power system is dangerous, be not suitable for studying.
The invention has the beneficial effects as follows: 1, combination switch is realized magnetizing inrush current control, and stability, fail safe are higher; 2, the peak value of magnetizing inrush current is controlled; By the angle of flow of control thyristor, can control the size of magnetizing inrush current; 3, under the safety condition of low-voltage, the situation of simulation electric power system magnetizing inrush current is analyzed various magnetizing inrush current operating modes; 4, form the magnetizing inrush current waveform of readable data, can compare with result of calculation, be convenient to calculate and the comparison of testing, guarantee correctness, the reliability of research work.
Description of drawings
Fig. 1 is the system schematic that realization magnetizing inrush current of the present invention produces;
Fig. 2 is the schematic diagram of circuits for triggering of the present invention;
Fig. 3 is voltage zero-cross detecting unit of the present invention;
Fig. 4 is communication unit of the present invention;
Fig. 5 is driver element of the present invention;
Fig. 6 is combination switch control software flow pattern of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the present invention will be further described by embodiment.
With reference to Fig. 1, in an embodiment, a kind of generation device of three-phase transformer magnetizing inrush current, comprise circuit breaker, thyristor, A.C. contactor, on/off switch control trigger board and three phase transformers, two thyristors and an A.C. contactor of three groups of reverse parallel connections compose in parallel a combination switch, are connected between the front end and circuit breaker of three transformers; Provide triggering signal by on/off switch control trigger board, thyristor is triggered at the phase angle of regulation, close a floodgate when being implemented in the required voltage phase angle; On/off switch control trigger board produces different voltage switching-on phase angles, produces different magnetizing inrush current values; Simultaneously, current continuity in first cycle of thyristor, cutoff thyristor behind the one-period closes a floodgate successfully in the one-period of A.C. contactor after thyristor closes a floodgate, and guarantees current continuity, realizes separating brake control by A.C. contactor.
The present invention also is provided with host computer, and control on/off switch control trigger board produces different voltage switching-on phase angles, produces different magnetizing inrush current values.
A kind of production method of three-phase transformer magnetizing inrush current: circuit breaker closes a floodgate first, and the assurance system is closed a floodgate and separating brake by on-load switch control only; Host computer sends switching-on phase angle set point by serial communication to the single-chip microcomputer on the on/off switch control trigger board, single-chip microcomputer utilizes data acquisition function, gather the main circuit voltage signal, behind the alternating voltage positive going zeror crossing, the Trigger Angle of control forward thyristor produces the magnetizing inrush current of out of phase, oppositely thyristor voltage zero cross fired afterflow, the UNICOM that connects simultaneously the A.C. contactor holding circuit; Behind system stability, send separating brake phase angle set point by host computer to the single-chip microcomputer on the on/off switch control trigger board, Single-chip Controlling circuit breaker or thyristor separating brake form different remanent magnetism constantly; So both guarantee the accurately controlled of switching-on phase, eliminated again the harmful effect that thyristor may bring in each cycle switch action; Combination switch, the thyristor of two reverse parallel connections and A.C. contactor compose in parallel one group, totally three groups, control voltage switching-on phase angle, three-phase transformer high-pressure side or low pressure windings in series enter combination switch, opposite side winding open circuit or short circuit form zero load or short-circuit condition, for generation of the magnetizing inrush current of different conditions.
With reference to Fig. 2, Fig. 2 is on/off switch control trigger board circuit theory frame.
On/off switch control trigger board is comprised of single-chip microcomputer, voltage zero-cross detecting unit, communication unit, driver element, pulse transformer.
The voltage zero-cross detecting unit is comprised of voltage transformer, operational amplifier, as shown in Figure 3.This unit is converted to the low pressure square-wave signal with system's ac high voltage signal, can obtain comparatively accurately the system voltage zero crossing constantly.
Communication unit is the passage of host computer and single-chip machine information exchange, host computer utilizes operation interface to set after the switching-on phase angle, be converted to the serial communication signal, be converted to the signal that single-chip microcomputer can be identified by communication unit, single-chip microcomputer just can trigger thyristor and A.C. contactor by set point like this.
Communication unit is that core forms two kinds of communication modes by MAX3223 and the ADM2483 of U.S.'s letter respectively, as shown in Figure 4.Dual mode can realize that a host computer to the Collaborative Control of a plurality of single-chip microcomputers, finishes more content of the test.
Driver element is comprised of High-Speed Coupled Device 6N137, transistor 9013, Darlington transistor BU406, as shown in Figure 5.Because the Micro Controller Unit (MCU) driving ability is little, withstand voltage low, can not provide thyristor to trigger required electric current, magnitude of voltage, so the triggering signal that single-chip microcomputer sends need to be isolated amplification by driver element, it is open-minded to trigger thyristor.
The pulse signal of single-chip microcomputer output is through High-Speed Coupled Device 6N137 isolation, the two-stage power amplifier that forms through transistor 9013, Darlington transistor BU406 again, and the pulse transformer primary coil has been finished the isolation enlarging function of small-signal.
Pulse transformer adopts the pulse triggering mode.The drive pulse signal that amplifies through overdrive circuit is coupled to a pair limit from the former limit of pulse transformer, be connected to forward and reverse gate circuit transistor gate by terminal JP1, JP2, and it is open-minded to trigger thyristor.Through the pulse transformer isolation, both guaranteed that the high-voltage great-current thyristor can be effectively open-minded, the high-voltage great-current of system and on/off switch control trigger board are kept apart, be reliable, the safe operation of whole on/off switch control trigger board.
Combination switch control software flow pattern as shown in Figure 6.
The present invention is under the safety condition of low-voltage, and the situation of simulation electric power system magnetizing inrush current is analyzed various magnetizing inrush current operating modes.Form the magnetizing inrush current waveform of readable data, can compare with result of calculation, be convenient to calculate and the comparison of testing, by the application of combination switch, further guarantee correctness and the reliability of research work.
Claims (6)
1. the generation device of a three-phase transformer magnetizing inrush current, it is characterized in that: comprise circuit breaker, thyristor, A.C. contactor, on/off switch control trigger board and three phase transformers, two thyristors and an A.C. contactor of three groups of reverse parallel connections compose in parallel a combination switch, are connected between the front end and circuit breaker of three transformers; Provide triggering signal by on/off switch control trigger board, thyristor is triggered at the phase angle of regulation, close a floodgate when being implemented in the required voltage phase angle; On/off switch control trigger board produces different voltage switching-on phase angles, produces different magnetizing inrush current values; Simultaneously, current continuity in first cycle of thyristor, cutoff thyristor behind the one-period closes a floodgate successfully in the one-period of A.C. contactor after thyristor closes a floodgate, and guarantees current continuity, realizes separating brake control by A.C. contactor.
2. the generation device of a kind of three-phase transformer magnetizing inrush current according to claim 1 is characterized in that: also be provided with host computer, control on/off switch control trigger board and produce different voltage switching-on phase angles, produce different magnetizing inrush current values.
3. the generation device of a kind of three-phase transformer magnetizing inrush current according to claim 1 and 2, it is characterized in that: also be provided with TT﹠C system, comprise oscilloscope, ammeter pincers and voltmeter pincers, cooperate ammeter pincers and voltmeter pincers to carry out voltage acquisition and current acquisition with oscilloscope, finish magnetizing inrush current is measured.
4. a right to use requires 1 device that limits to produce the method for three-phase transformer magnetizing inrush current, it is characterized in that providing triggering signal by on/off switch control trigger board, thyristor is triggered at the phase angle of regulation, close a floodgate when being implemented in the required voltage phase angle; Closing a floodgate in the different voltage switching-on phase angle of on/off switch control trigger board control, can produce different magnetizing inrush current values; Simultaneously, current continuity in first cycle of thyristor, cutoff thyristor behind the one-period closes a floodgate successfully in the one-period of A.C. contactor after thyristor closes a floodgate, and guarantees current continuity, realizes separating brake control by A.C. contactor.
5. the production method of a kind of three-phase transformer magnetizing inrush current according to claim 4 is characterized in that: also be provided with host computer, the work of control on/off switch control trigger board; By comprising the TT﹠C system of oscilloscope, ammeter pincers and voltmeter pincers, cooperate ammeter pincers and voltmeter pincers to carry out voltage acquisition and current acquisition with oscilloscope, finish magnetizing inrush current is measured.
6. the production method of a kind of three-phase transformer magnetizing inrush current according to claim 5, it is characterized in that: circuit breaker closes a floodgate first, and the assurance system is closed a floodgate and separating brake by on-load switch control only; Host computer sends switching-on phase angle set point by serial communication to the single-chip microcomputer on the on/off switch control trigger board, single-chip microcomputer utilizes data acquisition function, gather the main circuit voltage signal, behind the alternating voltage positive going zeror crossing, the Trigger Angle of control forward thyristor produces the magnetizing inrush current of out of phase, oppositely thyristor voltage zero cross fired afterflow, the UNICOM that connects simultaneously the A.C. contactor holding circuit; Behind system stability, send separating brake phase angle set point by host computer to the single-chip microcomputer on the on/off switch control trigger board, Single-chip Controlling circuit breaker or thyristor separating brake form different remanent magnetism constantly; So both guarantee the accurately controlled of switching-on phase, eliminated again the harmful effect that thyristor may bring in each cycle switch action; Combination switch, the thyristor of two reverse parallel connections and A.C. contactor compose in parallel one group, totally three groups, control voltage switching-on phase angle, three-phase transformer high-pressure side or low pressure windings in series enter combination switch, opposite side winding open circuit or short circuit form zero load or short-circuit condition, for generation of the magnetizing inrush current of different conditions.
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| CN2012105779910A CN103078517A (en) | 2012-12-27 | 2012-12-27 | Generation device and method for magnetizing inrush current of three-phase transformer |
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| CN2012105779910A CN103078517A (en) | 2012-12-27 | 2012-12-27 | Generation device and method for magnetizing inrush current of three-phase transformer |
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Cited By (6)
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| CN103532456A (en) * | 2013-10-18 | 2014-01-22 | 中国海洋石油总公司 | Method for starting large transformer by utilizing solid state thyristor soft starter |
| CN104242224A (en) * | 2014-08-25 | 2014-12-24 | 国家电网公司 | Design method for input inductive load control parameters of compound switch |
| CN108155812A (en) * | 2018-01-16 | 2018-06-12 | 深圳市赛格瑞电子有限公司 | A kind of ac conversion circuit |
| CN110703146A (en) * | 2019-09-23 | 2020-01-17 | 长春长客-庞巴迪轨道车辆有限公司 | Excitation surge current measuring instrument |
| CN111751718A (en) * | 2020-05-20 | 2020-10-09 | 中国电力科学研究院有限公司 | Power electronic phase selection system and phase selection method thereof |
| CN112630642A (en) * | 2020-12-09 | 2021-04-09 | 中国电力科学研究院有限公司 | System and method for switching on-load tap-changer of transformer |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103532456A (en) * | 2013-10-18 | 2014-01-22 | 中国海洋石油总公司 | Method for starting large transformer by utilizing solid state thyristor soft starter |
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| CN111751718A (en) * | 2020-05-20 | 2020-10-09 | 中国电力科学研究院有限公司 | Power electronic phase selection system and phase selection method thereof |
| CN112630642A (en) * | 2020-12-09 | 2021-04-09 | 中国电力科学研究院有限公司 | System and method for switching on-load tap-changer of transformer |
| CN112630642B (en) * | 2020-12-09 | 2024-01-26 | 中国电力科学研究院有限公司 | System and method for switching on-load tap-changer of transformer |
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Application publication date: 20130501 |